Mobile flowback and produced water re-use system

ABSTRACT

A mobile water re-use system can include a chemical treatment apparatus, at least one weir tank in fluid communication with the chemical treatment apparatus, and two or more settling tanks in fluid communication with each other and at least one of the settling tanks in fluid communication with the weir tank. The weir tank can have a first end, a second end, an internal chamber, and a plurality of baffles that induce turbulent flow of fluid through the internal chamber. The settling tanks can provide, promote, facilitate, result in, and/or induce laminar flow of fluid through at least a portion of the internal chamber. Weir tanks, settling tanks, and method of treating flowback and produced water are also described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/872,131, filed Aug. 30, 2013, which is hereby incorporated in itsentirety by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to water treatment systems and, inparticular, to a mobile flowback water and/or produced water re-usesystem.

Description of Related Art

In a hydraulic fracturing process, fracturing fluids are injected underpressure into a bore hole. The pressure drives the fluid into cracks andfractures forcing such openings to become larger and to propagate. Theinjected fracturing fluids mix with groundwater, gas, and othermaterials. When the pressure is removed, the fluid mixture flows back tothe surface. Gas is then extracted from the fluid mixture. This fluidmixture, which is commonly referred to as “flowback water”, hasconcentrations of oil, grease, metals, sealants, salts, and otherunwanted materials. After the initial discharge of flowback water, thewell continues to produce oil, water, and various other materials. Thewater continually produced from the well is commonly referred to as“produced water” and is similar in composition to flowback water.

Due to the typical lack of water resources needed for drillingoperations, flowback and produced water are recycled for further use. Assuch, with the ongoing drilling for oil and gas, there is a high demandfor efficient recycling processes that can effectively remove unwantedmaterials from flowback and produced water.

SUMMARY OF THE INVENTION

Generally, provide is an improved mobile water re-use system and method.

In certain preferred and non-limiting embodiments, the present inventionis directed to a mobile water re-use system that can include a chemicaltreatment apparatus, at least one weir tank in fluid communication withthe chemical treatment apparatus, and two or more settling tanks influid communication with each other, where at least one of the settlingtanks is in fluid communication with the weir tank. The weir tank canhave a first end, a second end, an internal chamber, and a plurality ofbaffles that provide, promote, facilitate, result in, and/or induceturbulent flow of fluid through the internal chamber. The settling tankscan provide laminar flow of fluid through the internal chamber.

In certain preferred and non-limiting embodiments, the weir tankincludes baffles that extend up from a bottom portion of the internalchamber. These baffles can have an arm that extends out in a directiontoward the first end of the weir tank. The baffles can also becomeshorter toward the second end of the weir tank. In some preferred andnon-limiting embodiments, the weir tank further includes baffles thatextend down from a top portion of the internal chamber. The baffles thatextend down from the top portion of the internal chamber can bepositioned above the arms of the baffles that extend up from the bottomportion of the internal chamber. The weir tank can also have a fluidinlet at the first end and a fluid outlet at the second end. The fluidoutlet of the weir tank can include a hollow extension member thatextends to a selected height within the internal chamber. The hollowextension member can have a bell-shaped inlet.

In certain preferred and non-limiting embodiments, the settling tank ofthe mobile water re-use system can include a first end having a fluidinlet port and a fluid outlet port, a second end, an internal chamber,and an internal feed line positioned within the internal chamber. Theinternal feed line can have a first end connected to the fluid outletport and a second end that extends out toward the second end of thesettling tank. The settling tank can further include a baffle platepositioned between the second end of the internal feed line and thefirst end of the settling tank. The baffle plate can span the entirewidth of the internal chamber of the settling tank. The bottom perimeterof the baffle plate can be positioned below an opening at the second endof the internal feed line. Further, in some preferred and non-limitingembodiments, a gap can be formed between a top perimeter of the baffleplate and a top portion of the internal chamber of the settling tank.The mobile water re-use system can also include a holding tank in fluidcommunication with at least one of the settling tanks. The fluidcommunication between the at least one weir tank, two or more settlingtanks, and/or holding tanks can be established by fluid connectorshaving an internal diameter of greater than about 8 inches. In someembodiments, the mobile water re-use system is automatically controlledby a programmable logic controller, a computer, software, firmware,programmable instructions, and/or the like.

In certain preferred and non-limiting embodiments, the present inventionis also directed to a method of treating flowback and produced water.The method can include: transferring flowback and produced water to achemical treatment apparatus; mixing treatment chemicals with theflowback and produced water; transferring the mixture of treatmentchemicals and flowback and produced water to a weir tank having a firstend, a second end, an internal chamber, and a plurality of bafflespositioned throughout the internal chamber to provide, promote,facilitate, result in, and/or induce turbulent flow; transferring themixture of treatment chemicals and flowback and produced water to afirst settling tank that provides, promotes, facilitates, results in,and/or induces laminar flow; and transferring the mixture of treatmentchemicals and flowback and produced water to a second settling tank thatprovides, promotes, facilitates, results in, and/or induces laminarflow.

In another preferred and non-limiting embodiment, the method includes:transferring flowback and produced water to a chemical treatmentapparatus; mixing the flowback and produced water with treatmentchemicals; transferring the mixture of treatment chemicals and flowbackand produced water to a first weir tank having a first end, a secondend, an internal chamber, and a plurality of baffles positionedthroughout the internal chamber to provide, promote, facilitate, resultin, and/or induce turbulent flow through the internal chamber;transferring the mixture of treatment chemicals and flowback andproduced water back to the chemical treatment apparatus; mixing theflowback and produced water with additional treatment chemicals;transferring the mixture of treatment chemicals and flowback andproduced water to a second weir tank having a first end, a second end,an internal chamber, and a plurality of baffles positioned throughoutthe internal chamber to provide, promote, facilitate, result in, and/orinduce turbulent flow through the internal chamber; transferring themixture of treatment chemicals and flowback and produced water to afirst settling tank that provides, promotes, facilitates, results in,and/or induces laminar flow; and transferring the mixture of treatmentchemicals and flowback and produced water to a second settling tank thatprovides, promotes, facilitates, results in, and/or induces laminarflow.

In certain preferred and non-limiting embodiments, the methods describedabove can also include an initial step of transferring the flowback andproduced water to a filtering device or separate weir tank beforeentering the chemical treatment apparatus. Additionally, the methods oftreating flowback and produced water can include transferring themixture of treatment chemicals and flowback and produced water to athird settling tank that provides, promotes, facilitates, results in,and/or induces laminar flow and/or transferring the treated water to aholding tank after exiting the last settling tank. In some embodiments,the separated water can be transferred back to the chemical treatmentapparatus after exiting the last settling tank or holding tank and mixedwith additional treatment chemicals.

The present invention is also directed to a weir tank and a settlingtank as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a water re-use system according to oneembodiment of the present invention;

FIG. 2 is a top view of a water re-use system according to a secondembodiment of the present invention;

FIG. 3 is a top cross-sectional view of a chemical treatment apparatusaccording to one embodiment of the present invention;

FIG. 4 is a top cross-sectional view of a chemical treatment apparatusaccording to a second embodiment of the present invention;

FIG. 5 is a cross-sectional side view of a weir tank according to oneembodiment of the present invention;

FIG. 6 is a front view of the first end of the weir tank shown in FIG.5;

FIG. 7 is another cross-sectional side view of the weir tank shown inFIG. 5;

FIG. 8 is a front view of the second end of the weir tank shown in FIG.5;

FIG. 9 is a side view of the weir tank of FIG. 5;

FIG. 10 is a top view of the weir tank of FIG. 5;

FIG. 11 is a bottom view of the weir tank of FIG. 5;

FIG. 12 is a cross-sectional side view of a settling tank according toone embodiment of the present invention;

FIG. 13 is a front view of the first end of the settling tank shown inFIG. 12;

FIG. 14 is a front view of the second end of the settling tank shown inFIG. 12;

FIG. 15 is a side view of the settling tank of FIG. 12; and

FIG. 16 is a top view of the settling tank of FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION

For purposes of the description hereinafter, the terms “upper,” “lower,”“right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,”“longitudinal,” and derivatives thereof shall relate to the invention asit is oriented in the drawing figures. However, it is to be understoodthat the invention may assume alternative variations and step sequences,except where expressly specified to the contrary. It is also to beunderstood that the specific devices and processes illustrated in theattached drawings, and described in the following specification, aresimply exemplary embodiments of the invention. Hence, specificdimensions and other physical characteristics related to the embodimentsdisclosed herein are not to be considered as limiting.

In certain embodiments, referring to FIGS. 1-2, the present invention isdirected to a mobile water re-use system that may include a chemicaltreatment apparatus 4, weir tanks 6, settling tanks 8, and/or holdingtanks 10. As used herein, a “water re-use system” refers to a systemthat is capable of recycling and purifying flowback and produced waterobtained from a fracturing process. Further, a “mobile water re-usesystem” means that the chemical treatment apparatus 4, weir tanks 6,settling tanks 8, holding tanks 10, and other components that make upthe water re-use system are capable of being moved freely from onelocation to another. For example, in certain embodiments, the chemicaltreatment apparatus 4, weir tanks 6, settling tanks 8, and holding tanks10 can include wheels, tires, casters, rollers, and/or the like, whichallow them (individually and/or collectively) to be easily transportedto different locations for installation and/or mobilization.

As indicated, the mobile water re-use system can include a chemicaltreatment apparatus 4. In certain preferred and non-limitingembodiments, as shown in FIGS. 3-4, the chemical treatment apparatus 4may include a tank, trailer, or other apparatus that can house chemicals12, pumping devices 14, and/or fluid mixers 16. Suitable fluid mixers 16include, but are not limited to, conventional static fluid mixers thatcan uniformly mix the treatment chemicals 12 with the flowback andproduced water. The chemicals 12 mixed with the flowback and producedwater may include, but are not limited to, coagulation and flocculationcompounds and compositions. “Coagulation” refers to the transformationof a liquid to a soft, semisoft, or solid mass. As such, “coagulationcompounds and compositions” refers to compounds and compositions thatare capable of transforming substances such as sludge, oil, and othermaterials into soft, semisoft, and/or solid particles. “Flocculation”refers to the bridging or agglomeration of solid particles together intoclumps or “flocs”, thereby facilitating their separation from liquids,such as water. Thus, “flocculation compounds and compositions” refers tocompounds and compositions that can help agglomerate unwanted particlesfound in the flowback and produced water, such as the particles formedduring the coagulation process, to facilitate separation of theparticles from the water.

In certain preferred and non-limiting embodiments, as shown in FIG. 1,the chemical treatment apparatus 4 houses water treatment chemicals 12,one or more fluid mixers 16, and one or more pumping devices 14.Alternatively, as shown in FIG. 2, the chemical treatment apparatus 4houses water treatment chemicals 12 and one or more fluid mixers 16,with the pumping devices 14 separated from and connected to the traileror tank that houses the water treatment chemicals 12 and one or morefluid mixers 16. In both embodiments, the pumping devices 14 can be usedto transport flowback and produced water into the fluid mixers 16 withthe water treatment chemicals 12. The flowback and produced water can bepumped from a storage source where the flowback and produced water istransported after the fracturing process. For example, referring to FIG.1, flowback and produced water can be transported to the chemicaltreatment apparatus 4 from a storage pond or a holding tank 10, such asa conventional “frac tank”. In some of these embodiments, a separatefiltering device can be used to remove large particles and sediment fromthe flowback and produced water before it enters the chemical treatmentapparatus 4.

In another preferred and non-limiting embodiment, as shown in FIG. 2,flowback and produced water can first be pumped into a weir tank 6. Aswill described in detail below, the weir tank 6 is designed to trapparticles found within flowback and produced water. After flowingthrough the weir tank 6, flowback and produced water can pumped into thechemical treatment apparatus 4.

During operation, the pumping devices 14 associated with the chemicaltreatment apparatus 4 can transport flowback and produced water into thefluid mixers 16, where the flowback and produced water is mixed withcoagulation and/or flocculation chemicals 12. As shown in FIG. 3, thepumping devices 14 can be arranged in parallel. In another preferred andnon-limiting embodiment shown in FIG. 4, the pumping devices 14 can bearranged in series.

Further, in certain preferred and non-limiting embodiments, the chemicaltreatment apparatus 4 can be operated with manual controls. In otherembodiments, the chemical treatment apparatus 4 can be operatedautomatically using a controller such as, for example, a programmablelogic controller, a microprocessor, a central processing unit, and/orany other like device capable of processing data, such as a computingdevice having programmable instructions or software thereon, which, whenexecuted by a processor of the computing device, cause the processor toimplement or facilitate the described steps. The controller can also beused to operate all or a portion of the processing and control steps andinstructions of the water re-use system.

Referring to FIGS. 1 and 2, after mixing the treatment chemicals 12 withthe flowback and produced water, the mixture can be transported into aweir tank 6, where the treatment chemicals 12 interact with the flowbackand produced water. As shown in FIG. 5, the weir tank 6 may include afirst end 20, a second end 22, an internal chamber 24, and a pluralityof baffles 26 positioned throughout the internal chamber 24. Referringto FIG. 6, the first end 20 of the weir tank 6 can include a fluid inlet28, such as, for example, a feed line, where the flowback and producedwater can enter the weir tank 6. The first end 20 of the weir tank 6 canalso include a drain 30 that can be used to remove water, sludge, oil,and other materials found within the internal chamber 24 of the weirtank 6. In certain preferred and non-limiting embodiments, the mixtureof treatment chemicals 12 and flowback and produced water can betransported into the internal chamber 24 through the fluid inlet 28. Themixture can then flow through the internal chamber 24 comprising theplurality of baffles 26.

Referring to FIG. 5, the baffles 26 positioned throughout the internalchamber 24 of the weir tank 6 can be configured to allow fluids to flowto the second end 22 of the internal chamber 24, while simultaneouslycapturing sludge, oil, and other unwanted materials. The baffles 26 canalso provide, promote, facilitate, result in, and/or induce turbulentflow through the internal chamber 24. As used herein, the term“turbulent flow” refers to a type of fluid flow in which the fluidundergoes irregular fluctuations, or mixing. During turbulent flow, thespeed of the fluid is continuously undergoing changes in both magnitudeand direction. The turbulent flow can cause coagulation and/orflocculation compounds to react with the materials found in the flowbackand produced water.

In certain preferred and non-limiting embodiments, as shown in FIG. 5,the weir tank 6 can include baffles 26 that extend up from a bottomportion 32 of the internal chamber 24. The baffles 26 that extend upfrom the bottom portion 32 of the internal chamber 24 can each have anarm 34. The arm 34 can be attached and extend out from the baffle 26 ina direction toward the first end 20 of the weir tank 6. The baffles 26and arms 34 are configured to capture soft, semisoft, and/or solidparticles, such as sludge, oil, and other materials. For example, incertain preferred and non-limiting embodiments, the arm 34 can extendout at an angle from the baffle 26 to form a pocket like arrangementthat can capture soft, semisoft, and/or solid particles found in theflowback and produced water that is flowing to the second end 22 of theinternal chamber 24. In certain preferred and non-limiting embodiments,the angle formed between the arm 34 and baffle 26 is between about 10°and about 90°, in other preferred and non-limiting embodiments, betweenabout 30° and about 85°, and in still further preferred and non-limitingembodiments, between about 50° and about 80°.

In one preferred and non-limiting embodiment, the baffles 26 extendingup from the bottom portion 32 of the internal chamber 24 have differentheights and are shorter at the second end 22 of the internal chamber 24.For example, FIG. 5 shows the different heights of three baffles, whichare designated as H₁, H₂, and H₃, where the height of H₁ is greater thanthe height of H₂ and the height of H₂ is greater than the height of H₃.As such, in certain preferred and non-limiting embodiments,consecutively-placed baffles 26 can have different heights with thebaffle 26 positioned closer to the second end 22 of the internal chamber24 being shorter than the baffle 26 positioned closer to the first end20 of the internal chamber 24. Because the baffles 26 are shorter at thesecond end 22, the flowback and produced water flowing to the second end22 of the internal chamber 24 will cascade, or pour downward rapidly,over each baffle. The cascading of water provides, promotes,facilitates, results in, and/or induces turbulent flow causingcoagulation and/or flocculation compounds to react with the materialsfound in the flowback and produced water, thereby producing largerparticles or floccules of sludge, oil, and/or other unwanted materials.

As shown in FIG. 5, the weir tank 6 can further include baffles 26 thatextend down from a top portion 36 of the internal chamber 24. In certainpreferred and non-limiting embodiments, each baffle 26 that extends upfrom the bottom portion 32 of the internal chamber 24 can be positioneddirectly before and/or after a baffle 26 that extends down from the topportion 36 of the internal chamber 24. In one preferred and non-limitingembodiment, referring to FIG. 5, some of the baffles 26 that extend downfrom a top portion 36 of the internal chamber 24 can be positioned abovethe arms 34 that are attached to the baffles 26 extending up from thebottom portion 32 of the internal chamber 24. In this preferred andnon-limiting embodiment, flowback and produced water will flow throughthe space formed between the arm 34 and baffle 26 that extends down fromthe top portion 36 of the internal chamber 24. The flowback and producedwater can then flow over the baffle 26 that extends up from the bottomportion 32 of the internal chamber 24. As water is flowing through theinternal chamber 24, sludge, oil, and/or other unwanted materials can becaptured by both types of baffles 26. FIG. 7 is another cross-sectionalview of the weir tank and further illustrates the baffle 26 arrangementsdescribed herein. It is noted that the baffles 26 can be positionedwithin the internal chamber 24 of the weir tank 6 to form otherarrangements and are not limited to the embodiments described above.

Once the flowback and produced water reaches the second end 22 of theinternal chamber 24, it can exit the weir tank 6. As shown in FIG. 8,the water can exit second end 22 of the weir tank 6 through a fluidoutlet 38. The second end 22 of the weir tank 6 can also include a drain40 that can be used to remove water, sludge, oil, and/or other materialsfound within the internal chamber 24 of the weir tank 6.

In certain embodiments, and referring to FIGS. 5 and 7, the fluid outlet38 can include a hollow extension member 42, such as a pipe or feedline. As further shown in FIGS. 5 and 7, the hollow extension member 42may include a bell-shaped inlet that extends to a selected height withinthe internal chamber 24 of the weir tank 6. The raised bell shaped inlethelps prevent unwanted materials found on the bottom of the internalchamber 24 from exiting the weir tank 6. After entering the hollowextension member 42, flowback and produced water can exit the internalchamber 24 of the weir tank 6 through the fluid outlet 38. In certainpreferred and non-limiting embodiments, the flowback and produced waternaturally flows out through the fluid outlet 38 in a laminar flow. Asused herein, “laminar flow” refers to a fluid that flows in parallellayers without disruption between the layers and in which there islittle or no turbulence, i.e., little or no turbulent flow.

As indicated above, the baffles 26 positioned throughout the internalchamber 24 of the weir tank 6 can capture sludge, oil, and/or otherundesirable materials. While some of these materials can be removed fromthe internal chamber 24 through drains 30, 40 located at the first end20 and second end 22 of the weir tank 6, large amounts of thesematerials may remain in the internal chamber 24. Therefore, as shown inFIG. 9, the materials that remain within the internal chamber 24 can beremoved through small access openings 44 located on the weir tank 6. Asfurther shown in FIG. 9, the weir tank 6 can also include manways 46 orlarger access openings. The manways 46 allow a person to enter the weirtank 6 to inspect, modify, repair, and/or clean the internal chamber 24.Small access openings 44 and/or manways 46 can be positioned anywhere onthe weir tank 6. For instance, small access openings 44 and/or manways46 can be positioned on the sides of the weir tank 6 (see FIG. 9), thetop of the weir tank 6 (see FIG. 10), the bottom of the weir tank 6 (seeFIG. 11), and/or the ends of the weir tank 6 (see FIGS. 6 and 8).

In one preferred and non-limiting embodiment, the flowback and producedwater is first mixed in the chemical treatment apparatus 4 withcoagulation chemicals 12 and then transported to a weir tank 4 aspreviously described. In such embodiments, the flowback and producedwater can be transported back to the chemical treatment apparatus 4after exiting the weir tank 6. The flowback and produced water can thenbe mixed with flocculation chemicals 12. After mixing the flowback andproduced water with flocculation chemicals 12, the water can betransported to a second weir tank 48 as shown in FIGS. 1 and 2. Thesecond weir tank 48 can be configured in the same manner as the firstweir tank 6 to provide, promote, facilitate, result in, and/or induceturbulent flow and capture unwanted materials found within the water.When the treated water exits the second weir tank 48, the water can betransported to a first settling tank 8.

In another preferred and non-limiting embodiment, the flowback andproduced water can be mixed simultaneously with both flocculation andcoagulation chemicals 12. In these embodiments, flowback and producedwater can react with the flocculation and coagulation chemicals 12 in asingle weir tank 6. As such, when the treated water exits the first weirtank 6, the water can be transported directly to a first settling tank8.

In certain preferred and non-limiting embodiments, the flowback andproduced water is pumped out of the internal chamber 24 of the weir tank6 or 48 and to a first settling tank 8. Alternatively, in otherembodiments, the flowback and produced water naturally flows out throughthe fluid outlet 38 in a laminar flow to the first settling tank 8. Asshown in FIGS. 1 and 2, a fluid connector 50 can be used to transfer theflowback and produced water to the first settling tank 8. Suitable fluidconnectors 50 include, but are not limited to, plastic piping, such aspoly-pipe. In certain preferred and non-limiting embodiments, the fluidconnector 50 can be designed or configured to provide, promote,facilitate, result in, and/or induce laminar flow to the settling tank8. For example, the fluid connector 50 can have a diameter that allowsthe water to flow naturally into the settling tank 8 without creatingturbulence. In certain preferred and non-limiting embodiments, the fluidconnector 50 has a diameter of greater than 8 inches, or greater thanabout 10 inches. In one embodiment, the fluid connector 50 has adiameter of about 12 inches or greater. In addition, the fluid connector50 extending between the various tanks can form a particular shapeincluding, but not limited to, a horseshoe-shape that provides,promotes, facilitates, results in, and/or induces laminar flow.

As indicated, flowback and produced water can be transported from a weirtank 6 or 48 and into a first settling tank 8 by way of a fluidconnector 50. Referring to FIG. 12, the settling tank 8 can have a firstend 60, a second end 62, and an internal chamber 64 with at least onebaffle plate 66. As shown in FIG. 13, the first end 60 of the settlingtank 8 can include a fluid inlet port 68 and a fluid outlet port 70. Thefirst end 60 of the settling tank 8 can also include small accessopenings 44, manways 46, and a drain 72. As shown in FIG. 14, the secondend 62 of the settling tank 8 can also include small access openings 44and a drain 74. In certain preferred and non-limiting embodiments, smallaccess openings 44 and/or manways 46 are also positioned on the sides ofthe settling tank 8 (see FIG. 15) and on the top of the settling tank 8(see FIG. 16).

In certain preferred and non-limiting embodiments, referring to FIG. 12,an internal feed line 75 can be positioned within the internal chamber64 of the settling tank 8. The internal feed line 75 can have a firstend 76 and second end 77. The first end 76 can be connected to the fluidoutlet port 70 of the settling tank 8, and the second end 77 can extendout toward the second end 62 of the settling tank 8. The second end 77of the internal feed line 75 can have an opening 78 where water andother fluids can enter. The opening 78 can comprise a bell-shaped inletthat extends to a selected height within the internal chamber 64 of thesettling tank 8. The elevated bell-shaped inlet prevents unwantedmaterials from entering the feed line 75.

As further shown in FIG. 12, the at least one baffle plate 66 can bepositioned between the opening 78 at the second end 77 of the internalfeed line 75 and the first end 60 of the settling tank 8. The baffleplate 66 can span the entire width of the internal chamber 64 and canhave a top perimeter 80 and a bottom perimeter 82. The bottom perimeter82 can be positioned below the opening 78 of the internal feed line 75to prevent sludge and other materials from flowing into the opening 78.Further, a gap may be formed between the top perimeter 80 of the baffleplate 66 and a top portion 84 of the internal chamber 64 of the settlingtank 8. The gap can allow sludge and other materials to flow past thebaffle plate 66 if there is an excessive amount of these materialswithin the settling tank 8. The settling tank 8 can also have othercomponents. For example, in certain preferred and non-limitingembodiments, the settling tank 8 can have heating tubes 88,pressure/vacuum relief valves 90, electronic gauge ports 92, and thelike (see FIGS. 12 and 16).

During operation, flowback and produced water enters the settling tank 8through the fluid inlet port 68 by way of the fluid connector 50. Asflowback and produced water enters the first end 60 of the settling tank8, water begins to flow to the second end 62 and fill the internalchamber 64. In certain embodiments, the flowback and produced water canflow through the settling tank 8 with a laminar flow. The laminar flowallows particles to naturally separate from the water. Once the waterreaches a certain height within the internal chamber 64 of the settlingtank 8, the water can enter the opening 78 of the internal feed line 75and flow toward the fluid outlet port 70 at the first end 60 of thesettling tank 8. In certain preferred and non-limiting embodiments, theinternal feed line 75 is designed to provide, promote, facilitate,result in, and/or induce laminar flow. For example, the internal feedline 75 can have an internal diameter of greater than about 8 inches,or, in another example, greater than about 10 inches, to provide,promote, facilitate, result in, and/or induce laminar flow. In onepreferred and non-limiting embodiment, the internal feed line 75 has adiameter of about 12 inches or greater.

Referring back to FIGS. 1 and 2, the treated flowback and produced watercan flow to a second settling tank 94 after exiting the first settlingtank 8. The water can naturally flow to the second settling tank 94through a fluid connector 50 as described above. The second settlingtank 94 can have the same design as the first settling tank 8 tonaturally separate unwanted particles from the water. If desired, themobile water re-use system can include additional settling tanks 96.Thus, in certain preferred and non-limiting embodiments, the mobilewater re-use system can include two or more, three or more, or even fiveor more settling tanks 8. For instance, as shown in FIGS. 1 and 2, watercan naturally flow to a third settling tank 96 after exiting the secondsettling tank 94.

In certain embodiments, the treated water can be transported back to thechemical treatment apparatus 4 after exiting the last settling tank (forexample, the second settling tank 94, the third settling tank 96, or anadditional settling tank). In another preferred and non-limitingembodiment, the treated water can be transported to a holding tank 10for storage, and, if desired, the water can be transported back to thechemical treatment apparatus 4 at a later time. After being transportedback to the chemical treatment apparatus 4, the water can be mixed inthe fluid mixers 16 with chemicals 12 such as pesticides,antimicrobials, and the like to deter biological infestation and growth.For example, the water can be mixed with biocide to protect againstbiological and chemical contamination. The types of chemicals 12 thatcan be mixed with the treated water are not so limited and can includeany chemical that is desired.

As indicated above, the present invention is also directed to a methodof treating flowback and produced water. In certain preferred andnon-limiting embodiments, the method includes transporting flowback andproduced to a chemical treatment apparatus 4 comprising chemicals 12,pumping devices 14, and/or fluid mixers 16. Alternatively, in otherpreferred and non-limiting embodiments, the flowback and produced wateris first transported to a separate filtering device or a weir tank 6 toremove large particles and sediment from the flowback and produced waterbefore it enters the chemical treatment apparatus 4. After entering thechemical treatment apparatus 4, the flowback and produced water can bemixed with treatment chemicals 12 including, but not limited to,coagulation and flocculation compounds and compositions.

In certain preferred and non-limiting embodiments, the method furtherincludes transferring the mixture of treatment chemicals 12 and flowbackand produced water to a weir tank 6 comprising a first end 20, a secondend 22, an internal chamber 24, and a plurality of baffles 26 positionedthroughout the internal chamber 24. The baffles 26 can be arranged inany of the embodiments previously described to provide, promote,facilitate, result in, and/or induce turbulent flow through the internalchamber 24 while capturing sludge, oil, and/or other unwanted materials.After reaching the second end 22 of the weir tank 6, the water can exitthe fluid outlet 38, which may include a hollow extension member 42 witha bell shaped inlet that extends to a selected height within theinternal chamber 24 of the weir tank 6.

In one preferred and non-limiting embodiment, the method includestransferring the flowback and produced water back to the chemicaltreatment apparatus 4 after exiting the weir tank 6. The flowback andproduced water can then be mixed with additional treatment chemicals 12and transferred to a second weir tank 48. The second weir tank 48 can beconfigured in the same manner as the first weir tank 6 to provide,promote, facilitate, result in, and/or induce turbulent flow and captureunwanted materials contained within the water. When the treated waterexits the second weir tank 48, the water can be transported to a firstsettling tank 8. In another preferred and non-limiting embodiment, theflowback and produced water is not transferred back to the chemicaltreatment apparatus 4 after exiting the first weir tank 6. Rather, inthis embodiment, the method includes transferring the flowback andproduced water directly to a settling tank 8 after exiting the firstweir tank 6.

As previously described, the settling tank 8 can be designed to provide,promote, facilitate, result in, and/or induce laminar flow and allowparticles to naturally separate from the water. For instance, in certainembodiments, the first settling tank 8 comprising a first end 60, asecond end 62, and an internal chamber 64 with at least one baffle plate66. As water enters the first end 60 of the settling tank 8, it willstart filing the internal chamber 64 without causing turbulent flow.Once the water reaches a certain height, the water can flow past the atleast one baffle plate 66, into the internal feed line 75 and out theoutlet port 70 at the first end 60 of the settling tank 8 where it istransferred to a second settling tank 94 through laminar flow. This sameseparation process can be repeated in the second settling tank 94.

In certain preferred and non-limiting embodiments, the method furtherincludes transferring the flowback and produced water to additionalsettling tanks 8 as may be deemed necessary to separate particles fromthe water. After exiting the last settling tank (for example, the secondsettling tank 94, the third settling tank 96, or an additional settlingtank), the water can be transported back to the chemical treatmentapparatus 4 or to a holding tank 10. As indicated, the water re-usesystem is mobile and can be transported from one location to another.Thus, after the flowback and produced water is treated according to thepresent invention, all or part of the system can be easily transportedto a different location.

While various embodiments were provided in the foregoing description,those skilled in the art may make modifications and alterations to theseembodiments without departing from the scope and spirit of theinvention. For example, it is to be understood that this disclosurecontemplates that, to the extent possible, one or more features of anyembodiment can be combined with one or more features of any otherembodiment. Accordingly, the foregoing description is intended to beillustrative rather than restrictive. The invention describedhereinabove is defined by the appended claims and all changes to theinvention that fall within the meaning and the range of equivalency ofthe claims are to be embraced within their scope.

What is claimed is:
 1. A weir tank for treating flowback and producedwater, comprising: a first end; a second end; an internal chamber; aplurality of baffles that extend up from a bottom portion of theinternal chamber, the baffles extending up from the bottom portion ofthe internal chamber comprising an arm that extends out in a directiontoward the first end of the weir tank, wherein the plurality of bafflesthat extend up from the bottom portion of the internal chamber induceturbulent flow of fluid through the internal chamber and become shortertoward the second end of the weir tank; and a plurality of baffles thatextend down from a top portion of the internal chamber, the bafflesextending down from the top portion of the internal chamber positionedabove the arms of the baffles extending up from the bottom portion ofthe internal chamber.
 2. The weir tank of claim 1, wherein the weir tankfurther comprises a fluid inlet at the first end of the weir tank and afluid outlet at the second end of the weir tank.
 3. The weir tank ofclaim 2, wherein the fluid outlet comprises a hollow extension memberthat extends to a selected height within the internal chamber.
 4. Theweir tank of claim 3, wherein the hollow extension member comprises abell-shaped inlet.
 5. A settling tank for treating flowback and producedwater, comprising: a first end comprising a fluid inlet port and a fluidoutlet port; a second end; an internal chamber; an internal feed linepositioned within the internal chamber, the internal feed line having afirst end connected to the fluid outlet port and a second end having anopening that extends out toward the second end of the settling tank; anda baffle plate positioned between the opening of the internal feed lineand the first end of the settling tank, wherein the settling tankprovides laminar flow of fluid through the internal chamber.
 6. Thesettling tank of claim 5, wherein the baffle plate spans the entirewidth of the internal chamber of the settling tank.
 7. The settling tankof claim 6, wherein a bottom perimeter of the baffle plate is positionedbelow the opening of the internal feed line.
 8. The settling tank ofclaim 7, wherein a gap is formed between a top perimeter of the baffleplate and a top portion of the internal chamber of the settling tank.